unsigned short int r; unsigned short int c1 = 52845; unsigned short int c2 = 22719; #include "t1crypt.h" unsigned char t1_encrypt(unsigned char plain) { unsigned char cipher; cipher = (plain ^ (r >> 8)); r = (cipher+r)*c1 + c2; return cipher; } void t1_crypt_init (unsigned short int key) { r = key; } unsigned char t1_decrypt(unsigned char cipher) { unsigned char plain; plain = (cipher ^ (r>>8)); r = (cipher+r)*c1 + c2; return plain; }